IJSRSET173341 | 21 May 2017 | Accepted: 31 May 2017 | May-June-2017 [(2)3: 179-188]
© 2017 IJSRSET | Volume 3 | Issue 3 | Print ISSN: 2395-1990 | Online ISSN : 2394-4099
Themed Section: Engineering and Technology
179
A Review of the Roof Design and its Influence on the Thermal
Performance of Buildings in Equator Area with Warm Humid Climate
B. Rudianto
1
, S. N. N. Ekasiwi
2
, I. G. N. Antaryama
2
1
Ph.D Program, Department of Architecture, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
2
Department of Architecture, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
ABSTRACT
In equator area, roof is building element that plays a role in protecting the building from solar radiation because the
sun traverses almost perpendicular. The character of warm humid climate is not only high radiation but also high
humidity and rainfall. The roof design in the past has a large roof shape, the use of local materials and ventilation
existed to get a good thermal performance. Roof designs of modern building mostly have a variation on the roof
shape, materials and construction that may affect the thermal performance. This study provides a review of research
on the roof design and its influence on the thermal performance of building in warm humid climate. For this
purpose, all papers are categorized in two main groups namely pitched-roof and flat-roof. This study shows that the
variety of roof shape, materials and construction on modern roof design causes each roof design has the different
strategy to improve thermal performance. Roof designs of modern building rely on insulation material to reduce heat
transfer. The strategy to reduce radiant heat transfer on pitched-roof depends on kind of insulation and its placement.
The strategy to reduce conduction heat transfer on flat-roof depends on kind of insulation and air gap thickness.
Combination of insulation material and cool paint on both roof designs is not only reduces heat flux but also lowers
surface temperature so that contributes to reduce heat dispersion to the surrounding air. Natural ventilation is still
required on certain roof designs to help improve the thermal performance of buildings.
Keywords: Roof Design, Thermal Performance, Heat Transfer, Roof Shape, Insulation Material, Cool Paint, Warm
Humid Climate
I. INTRODUCTION
In the past, the roof was characteristic that determines
the building shape and the appearance of settlements of
a climate region. The difference in appearance was a
manifestation of its environmental conditions that
utilized to get comfort and health [1]. The roof is the
main source of heat gain on buildings in equator area
with warm humid climate [2]; [3]; [4]; [5]. The area of
warm humid climate is located geographically at
latitude between 15° N - 15° S. The character of its
climate has the monthly temperatures about 20°-30°C
with little diurnal range. Humidity through the year
above 60% with maximum about 90-100%. The annual
rainfall exceeds 1000 mm. The high temperature and
high humidity cause excessive evaporation that can not
be easily removed [4]. Heat can be removed by
ventilation in small differences between indoor and
outdoor temperature. On a large temperature difference
due to the solar radiation on the roof has caused the high
of mass radiation temperature on the ceiling. Therefore,
the roof is building element that important to note [5].
The building envelope keeps the heat transfer into the
buildings most of the day. Improving thermal
performance of building is an attempt to reduce thermal
load, that means reducing energy consumption for
cooling [7]. In warm humid climate, the roof must be
designed to minimize solar heat gain and promote
ventilation. Roof shape with sharp slope angle creating
the volume of air as cavity. Ventilation existed to
remove unwanted heat. This kind of roof is not only to
form a large volume of air as cavity but also to drain off